Heat exchanger

ABSTRACT

Heat exchanger which is composed of a base plate ( 2 ), several cooling fins ( 3 ) and accumulator blocks ( 6 ), whereby the cooling fins ( 3 ) are fixed to the base plate ( 2 ) and the accumulator blocks ( 6 ) are pressed in the base plate or provided therein, characterised in that the base plate ( 2 ) and cooling fins ( 3 ) are made of a first metal alloy and in that the accumulator blocks ( 6 ) are made of a second metal alloy whereby the second metal alloy provides for a better heat conduction than the first metal alloy.

The present invention concerns a heat exchanger.

In particular, it concerns a heat exchanger that is compact andportable, onto which a tube and a head are connected to quickly cool orheat a mass or element.

It is already known that heat exchangers exist which make use of acompressor and a fluid for heating or cooling an element.

A disadvantage thereof is that such heat exchangers are usually largeand heavy, as a result of which they are difficult to move.

The present invention aims to remedy one or several of theabove-mentioned and other disadvantages.

To this end, the present invention concerns a heat exchanger which iscomposed of a base plate, several cooling fins and accumulator blocks,whereby the cooling fins are fixed to the base plate and the accumulatorblocks are pressed in the base plate or provided therein, whereby thebase plate and cooling fins are made of a first metal alloy, and theaccumulator blocks are made of a second metal alloy whereby the secondmetal alloy provides for a better heat conduction than the first metalalloy.

An advantage of a heat exchanger according to the invention is that theheat exchanger is cheaper and lighter than an embodiment that would beentirely made of the second metal alloy.

As a result, the heat exchanger can easily form a part of a compactdevice with which heat can be quickly transferred.

This is for example important to quickly warm up the muscles ofsportsmen/women and athletes. It restricts the time that is required totreat the sportsmen/women while their muscles are neverthelesssufficiently warmed up.

A second example is that a device according to the invention can also beused for certain patient treatments, offering the advantage that thetreatment is speeded up and will be more efficient.

In a preferred embodiment of a heat exchanger according to theinvention, the heat exchanger is screwed down to a strut through which afluid is guided via a tubular element.

Such a strut is known for example from patent BE 2006/0232.

A treatment head with a tube is preferably coupled to the heat exchangeraccording to the invention, whereby the head comprises two feed-throughelements, such that a good heat transfer is obtained and a closed liquidcircuit is realised with the heat exchanger.

An advantage of a heat exchanger according to the preferred embodimentof the invention is that a relatively small amount of liquid must be ledthrough the heat exchanger for a certain volume of heat transfer.

In order to better explain the characteristics of the invention, thefollowing preferred embodiments of a heat exchanger according to theinvention are described by way of example only, without being limitativein any way, with reference to the accompanying drawings, in which:

FIG. 1 schematically represents a heat exchanger according to theinvention, seen in perspective;

FIGS. 2 and 3 are sections of FIG. 1 according to lines II-II andIII-III respectively;

FIG. 4 shows a preferred embodiment of a heat exchanger according to theinvention;

FIG. 5 shows the construction of the above-mentioned embodiment fromFIG. 4;

FIG. 6 shows a preferred embodiment of the heat exchanger, coupled to atreatment head;

FIGS. 7 up to 13 included show details of the treatment.

FIG. 1 shows a heat exchanger 1 according to the invention which isprovided with a base plate 2 and cooling fins 3.

The base plate 2 and cooling fins 3 are preferably made of aluminium,and the cooling fins 3 are glued to the base plate 3.

FIG. 1 also shows how the base plate is provided with grooves 4 in whichthe cooling fins 3 are arranged for more lateral rigidity. Some of theouter cooling fins are hereby partly cut out on either side of theangles situated at the top and at the front.

FIGS. 2 and 3 show how accumulator blocks 6 are pressed in the bottom ofthe base plate 2, whereby the accumulator blocks 6 are made of amaterial which provides for a better heat conduction than the materialout of which the base block 2 and the cooling fins 3 are made.

The accumulator blocks 6 are preferably made of copper or a copperalloy, and the base plate 2 and cooling fins 3 of aluminium or analuminium alloy.

It should be noted that the accumulator blocks 6 must not necessarily bepressed in the base plate 2, but it is probably more appropriate inorder to obtain a more durable heat exchanger 1 according to theinvention, since a copper alloy is more difficult to process than analuminium alloy, which can be easily glued.

FIG. 4 shows a preferred embodiment of a heat exchanger 1 according tothe invention whereby the heat exchanger 1 is contained in a cover plate8 which is screwed down on the base plate 2 by means of screws 9. Thecover plate 8 hereby runs in the longitudinal direction together withthe cooling fins 3. At the front, the heat exchanger 1 is covered with afan module 10 placed crosswise onto the cooling fins 3.

On either side, at the bottom of the cover plate 2, are fixed sideplates 11 under which is provided a frame 12. This frame is providedwith crosswise holes 13 and 14.

FIG. 5 shows the assembly of a heat exchanger 1 according to FIG. 4 andit shows how the base plate 2, on the lower side where the accumulatorblocks 6 are situated, is screwed down to a strut 15 through which afluid is led by two (or several) tubular elements 16.

Such a strut 15 is disclosed in patent BE 2006/0232. For the sake ofcompleteness, it should be mentioned that such a strut 15 has apredominantly U-shaped cross section with a back wall on which is eachtime provided a protruding leg on two opposite edges, which legs areprovided with a cross collar on their free edges extending to theoutside of the U-shaped strut, whereby the outside' of the back wall isentirely or almost entirely flat, and whereby the strut 15 is providedwith a tubular element 16 on its open side, made in one piece with thestrut 15 and extending parallel to the legs.

An advantage of such a strut 15 is that it can be extruded and,consequently, it can be made in many different sizes and in aneconomical manner.

FIG. 5 also shows how little chunks 17 are provided in the angles 5where the recesses of the cooling fins 3 are situated, such that the fanmodule 10 can be screwed down on them by means of screws 9.

The assembly is completed with a U-shaped pipe 18 which connects the twoelements 16 of the strut 15 to one another. Apart from that, bushes 19and rings 20 are used to guide the screws 9 of different lengthsthrough.

The use of a heat exchanger 1 according to the invention is simple andas follows.

FIGS. 1 to 3 included show that the essence of the heat exchanger 1consists of the use of accumulator blocks 6 which make contact with abase plate 2 and cooling fins 3. Since the accumulator blocks 6 conductthe heat better than the base plate 2 and cooling fins 3, they can bemade more compact so as to remove the required amount of heat.

As mentioned above, the accumulator blocks 6 are preferably made ofcopper or a copper alloy, and the base plate 2 and cooling fins 3 ofaluminium or an aluminium alloy.

Thus is obtained a heat exchanger 1 which combines the good heatconductivity of the copper alloy with the lighter weight and the lowercost price of an aluminium alloy in order to obtain a light and compactdevice which can quickly remove a required amount of heat.

In order to obtain a heat transfer over the accumulator blocks 6 that isas large as possible, the latter are made as smooth as possible, sinceroughness has a negative effect on the heat transfer. The blocks 6 mightfor example be polished to an average maximal roughness height of 4 m.

The working of a preferred embodiment of the heat exchanger 1 to be usedin such a device which is not shown in the figures can be best explainedby means of FIGS. 4 and 5.

If one wishes to cool an element quickly, a circuit with a coolingliquid can be led through the heat exchanger 1 via the feed hole 13. Thetubular elements 16 of the strut 15 will then give off the heat to theaccumulator blocks 6 which in turn will transfer the heat to the baseplate 2 and the cooling fins 3. The produced heat is sucked in by thefan module 10 and blown into the atmosphere. The U-shaped pipe 18 makessure that the cooling liquid is led via a loop formed of two tubularelements 16 in the case of the present figure, and that the heat istransferred to two accumulator blocks 6.

The cooling liquid then leaves the heat exchanger 1 via the outlet 14.To this outlet 14 can be coupled a tube or a pipe having a treatmenthead at its far end. This is appropriate for the physiotherapy treatmentof sportsmen/women and patients.

The heat exchanger 1 may also work with a closed liquid circuit for thephysiotherapy treatment of sportsmen/women, as is schematically shown inFIG. 6.

The treatment head 21 is then connected to the heat exchanger 1 by meansof a tube 22.

FIG. 7 shows how the treatment head 21 is formed of a head or a tip 23,a body 24 and a connecting piece 25. In the body are provided a smallfeed-through element 26 and a large feed-through element 27. Optionally,also a Peltier element 28 could be provided in the body 24.

By connecting this Peltier element 28 to a power source, the heattransfer or the cooling power can be accurately adjusted and the thermalexpansions of the feed-through elements 26 and 27 can be absorbed.

FIGS. 8 and 9 show how the small feed-through element 26 is provided atthe back with a preferably cylindrical, wider part 29 which changes in apreferably cylindrical, narrow part 30 towards the front, i.e. to thetip side of the treatment head 21. The wider part 29 is provided withoutside thread 31 on its (casing) surface. The small feed-throughelement 26 also has a supply opening 32 and a return opening 33.Optionally, additional holes 34 may be provided which may possibly servefor the use of screws.

FIG. 10 shows how the large feed-through element 27 is provided with apreferably cylindrical, narrow part 35 which changes in a preferablycylindrical, wider part 36 towards the front, i.e. towards the tip sideof the treatment head 21. The narrow part 35 is hollow and provided withinternal thread 37 extending over a certain length at the back in thecavity 38, i.e. on the side of the connecting piece 25 of the treatmenthead 21. Additional holes 39 may be optionally provided in the widerpart 36, which may possibly serve to fix screws in.

The cross sections as shown in FIGS. 11, 12 and 13 show that thedimensions of the small feed-through element 26 and the largefeed-through element 27 are such that the diameter of the wider part 29of the small feed-through element 26 is practically equal to the innerdiameter of the narrow part 35 of the large feed-through element 27,such that the outer thread 31 of the small feed-through element 26 canmesh with the inner thread 37 of the large feed-through element 27 andboth feed-through elements 26 and 27 fit into one another.

The cavity 38 of the large feed-through element 27 is preferablyprovided with a stop 40 which can be used for the wider part 29 of thesmall feed-through element 26. In the part of the cavity 38 which isscreened by the stop 40 towards the tip side is preferably provided asecond internal thread 41.

Preferably, the height of the ribs of the above-mentioned second screwthread 41 is such that the inner diameter of this part of the cavity 38is practically as large or somewhat larger than the external diameter ofthe narrow part 30 of the small feed-through element 26.

FIGS. 6 and 13 show how, when the feed-through elements 26 and 27 arescrewed together and are provided in the treatment head 21, a closedliquid circuit is created together with the heat exchanger 1. Arrow A inFIG. 6 shows how the cooling liquid leaves the housing of the heatexchanger 1 via the outlet opening 14 and flows to the largefeed-through element 27 via the supply opening 32 according to arrow Cvia the supply duct 22A of the tube 22 according to arrows A′ and A″.The inner thread 41 is preferably made such that the cooling liquidflows between the ribs of the inner thread 41 and follows the helicalline towards the tip side of the treatment head 21.

As the cavity 38 at the stop 40 has an inner diameter which is almostequal to the outer diameter of the narrow part 30 of the smallfeed-through element 26, an immediate flow-back is avoided and anefficient flow of the cooling liquid to the tip side according to arrowC is obtained.

Via the return opening 33, the cooling liquid is driven according toarrow B″ from the large feed-through element 27 to the return duct 22Bof the tube 22 and thus to the inlet 13 of the frame 12 of the heatexchanger 1.

An advantage of the above-described embodiment of the treatment head 21is that, thanks to the large contact surface over and between the ribsof the inner thread 41, a more efficient heat transfer is obtained.

The feed-through elements 26 and 27 and the tip 23 are preferably madeof aluminium or brass or another material which provides a goodcompromise between a good transfer of heat and a light weight.

Compared to a traditional treatment head, the above-described embodimentof a heat exchanger 1 with a treatment head 21 aims to cool down from40° to 2° C. in one minute and a half; with a traditional treatmenthead, this would take three minutes. When treating tennis players, forexample, for whom only 90 seconds of treatment is allowed between twogames of a match, the physiotherapy treatment of spasms will be far moreefficient.

It is clear that the heat exchanger 1 with a treatment head 27 can berealised according to many different embodiments without departing fromthe principle of the invention.

Thus, it is clear that a strut 15 may have several pairs of tubularelements 16 which connect at the top with several pairs of accumulatorblocks 6 and have U-shaped pipes 18 on alternating sides, such that thecooling liquid is led several times over the heat exchanger 1. Therewill be several inlets 13 and outlets 14 then, of which at least oneinlet 13 can be connected to a return duct 22B and at least one outlet14 can be connected to a supply duct 22A of a tube 22.

It is also clear that the heat exchanger can be used to quickly heat aliquid whereby the heat transfer then takes place in the opposite sensefrom the one described above.

As a practical example of a heat exchanger 1 according to the inventionto be used for the treatment of sportsmen/women and patients, we thinkof a device weighing less than 10 kg, preferably less than 5 kg and evenbetter still less than 3 kg, whereby it uses litre of cooling liquid inthe latter case in order to be able to treat sportsmen/women for someten minutes and patients for some 20 to 30 minutes. The cover plate 8hereby has a length of some 25 cm and the lower frame measures some 20by 20 cm. This device replaces a compressor weighing 30 kg and whichconsequently is difficult to move. A device according to the invention,however, is compact and can be easily carried, such that asportsman/woman can for example be treated on the sports field itselfinstead of in a practice.

Optionally, sensors are provided in the frame 12 to measure thetemperatures for different positions within the heat exchanger 1 or tomeasure how much cooling liquid is flowing through the heat exchanger 1.It is clear that additional options may be provided.

It should be noted that in the above description, the longitudinal andcross direction, the front and rear side and the upper and lower sidespecifically refer to the drawings for simplicity's sake, but it isclear that they depend on the position of the observer and that they donot restrict the essence of the invention in any way.

The present invention is by no means restricted to the embodimentsdescribed above and represented in the accompanying drawings; on thecontrary, a massive cardboard heat exchanger according to the inventioncan be made in all sorts of ways while still remaining within the scopeof the invention.

1-14. (canceled)
 15. Heat exchanger, comprising a base plate, a plurality of cooling fins and accumulator blocks, said cooling fins being fixed along one side to the base plate and the accumulator blocks being pressed in the base plate or provided therein, said base plate and cooling fins being made of a first metal alloy and said accumulator blocks being made of a second metal alloy, said second metal alloy having higher heat conductivity than said first metal alloy.
 16. Heat exchanger according to claim 15, wherein the cooling fins and accumulator blocks are fixed to opposing sides of the base plate, and: the accumulator blocks and base plate are directed with their largest surfaces crosswise in relation to the largest surfaces of the cooling fins, the outer cooling fins each have recesses on one side at their corners on the top side opposite the side thereof connected to the base plate, the base plate having screw holes extending therethrough in the longitudinal and cross directions.
 17. Heat exchanger according to claim 16, wherein chunks with screw holes are provided in the recesses, and the base plate, cooling fins and accumulator blocks are enclosed by a cover plate; a fan module with screw holes which are aligned with recesses; and wherein the cover plate, fan module, chunks and base plate with the cooling fins are fastened together by means of screws.
 18. Heat exchanger according to claim 17, wherein the base plate is screwed down on a side where the accumulator blocks are located to an upper side of a strut by means of screws; and wherein two or an even number of tubular elements are provided on a lower side of the strut through which a liquid may be circulated.
 19. Heat exchanger according to claim 18, wherein side plates and a frame with holes are fastened to the strut by rings, bushes and screws, enabling the holes in the frame to be connected to uneven and even tubular elements of the strut, and enabling U-shaped pipes to be connected to successive tubular elements on alternating sides.
 20. Heat exchanger according to claim 15, including sensors fixed to or in the heat exchanger arranged to measure the temperature or the liquid flow or other data.
 21. Heat exchanger according to claim 15, wherein the lower side of each accumulator block is finished in such a way that the maximal average roughness height Ra amounts to 4μ.
 22. Heat exchanger according to claim 15, wherein the first metal alloy is aluminium or an aluminium alloy and the second metal alloy is copper or a copper alloy.
 23. Heat exchanger according to claim 19, wherein a tube, a liquid circuit, a liquid pump and a head are coupled to the holes that define an inlet and an outlet of the tubular element and a fluid is supplied to the tubular element.
 24. Heat exchanger according to claim 23, wherein a treatment head is coupled to the inlet and the outlet of the tubular element by a tube having a supply duct and a return duct, said supply duct being connected to the outlet of the tubular element and the return duct being connected to the inlet of the tubular element.
 25. Heat exchanger according to claim 24, wherein the treatment head comprises a tip, a body and a connecting piece; a small feed-through element and a large feed-through element being provided in the body, said large feed-through element having a cavity and the dimensions of the small feed-through element being such that the small feed-through element may be received at least partly in the cavity of the large feed-through element; wherein the small feed-through element has a supply opening through which a cooling liquid can flow from the supply duct of the tube to the large feed-through element and has a return opening through which cooling liquid can flow from the large feed-through element to the return duct of the tube.
 26. Heat exchanger according to claim 25, wherein the small feed-through element has a wider part on a side of the tube which is connected to a narrow part on the side of the tip of the treatment head and the large feed-through element has a wider part on a side of the tube which is connected to a narrow part on the side of the tip of the treatment head; the diameter of the wider part of the small feed-through element being substantially equal to the inner diameter of the narrow part of the large feed-through element.
 27. Heat exchanger according to claim 26, wherein the wider part of the small feed-through element has an outer thread and the narrow part of the large feed-through element has an inner thread, such that the outer thread of the small feed-through element may mesh with the inner thread of the large feed-through element of the treatment head.
 28. Heat exchanger according to claim 15, wherein the heat exchanger is configured as a device for the local treatment of human muscles, the device weighing less than 10 kg. 